Organic-electroluminescence device, process for its production and organic-electroluminescence display system

ABSTRACT

A composition containing a high-molecular compound having as a photo-crosslinkable group any of a cinnamoyl group, a cinnamylidene group, a chalcone residual group, an isocoumarin residual group, a 2,5-dimethoxystilbene residual group, a thymine residual group, a styrylpyridinium residual group, an α-phenylmaleimide residual group, an anthracene residual group and a 2-pyrone residual group, or an aromatic bisazide, is cross-linked by light irradiation via a mask to cure the composition in a prescribed pattern to form photoemission layers.

[0001] This application is based on Japanese Patent Application No.2000-165976 filed in Japan, the contents of which are incorporatedhereinto by reference.

BACKGROUND OF THE INVENTION

[0002] This invention relates to an organic-electroluminescence(hereinafter often “organic-EL”) device, a process for its production,and an organic-electroluminescence display system having the device.

[0003] In general, in notebook personal computers, PDAs (personaldigital assistants), mobile computers, portable information terminals,cellular phones and so forth, liquid-crystal display is chiefly used asflat-panel display. Also, in recent years, the proportion of usingliquid-crystal display in place of CRT (cathode ray tube) display isincreasing in desktop computers, too.

[0004] However, the liquid-crystal display has problems such that it hasinsufficient response speed, requires a large power consumption in thecase of backlighting systems, has a low luminance and contrast in thecase of reflection systems and has inferior visual anglecharacteristics.

[0005] Flat-panel display substitutive of such liquid-crystal displaymay include PDP (plasma display panel) and FED (field emission display).These, however, also has problems that they require a large powerconsumption, can not be made thin and are heavy-weight.

[0006] Accordingly, as display that can solve these problems inliquid-crystal display and other flat-panel display such as PDP and FEDat a stretch, organic-EL display is proposed (e.g., C. W. Tang et al.,Appl. Phys. Lett, 51, 913, 1987). This organic-EL display has varioussuperior characters such that it has a very higher response speed thanthe liquid-crystal display, has an excellent viewing angle due todisplaying by self light emission, can be made thin by half as much asthe liquid-crystal display because it has ordy one sheet as a necessaryglass substrate and hence can be light-weight and may require a smallerpower consumption than the backlighting-type liquid-crystal display.

[0007] Accordingly, the organic-EL display is expected as a prospectivemeans in the twenty-first century.

[0008] The organic-EL display uses, as luminescent devices, organic-ELdevices making use of organic compounds as luminescent materials. Theorganic-EL devices have basic structure in which the anode, aphotoemission layer and the cathode are superposed in this order on asubstrate. A hole transport layer between the anode and thephotoemission layer, and an electron transport layer between the cathodeand the photoemission layer are optionally provided. Color display bysuch organic-EL devices include full-color display bythree-primary-color dot matrixes, and multiple-color area color display.In either case, photoemission layers must be formed in prescribedpatterns.

[0009] As methods for forming the photoemission layers for colordisplay, the following methods (1) to (4) are known in the art.

[0010] (1) A method in which respective EL luminescent low-molecularmaterials for red, blue and green are separately mask-vacuum-depositedthree times;

[0011] (2) a method in which organic-EL blue-light emission is convertedinto red color and green color by means of color conversion layers;

[0012] (3) a method in which solutions of respective EL luminescenthigh-molecular materials for red, blue and green are coated by ink-jetprinting to coat three-primary-color materials separately; and

[0013] (4) a method in which white-color EL light backlighting and colorfilters are used in combination.

[0014] However, the method (1) of mask vacuum deposition has so poor aproductivity as to result in a high cost. Also, mask registration mustbe made inside a vacuum reactor, and it is difficult to achieve uniformfilm formation because of a difference in molecules' flying angle anddistance between the middle area and the peripheral area of a substrate.In addition, there is a problem that any dusting inside the vacuumdeposition reactor may cause film defects.

[0015] The method (2) of color conversion requires the color conversionlayers other than organic-EL layers formed of EL luminescenthigh-molecular materials, and has a problem that many steps must beprovided. In addition thereto, there is another problem thatphotoemission efficiency may lower because of a loss at the time ofcolor conversion.

[0016] The method (3) of ink-jet coating requires dams for separatingdots of EL luminescent high-molecular materials, and hence involves alow aperture percentage, resulting in a low effective luminance.Moreover, a long tact time is required because any whole-surfaceone-time coating can not be performed, resulting in a high costespecially in the case that large number of organic EL devices areproduced in one lump substrate. There is also a problem on how to keepthe quality of inks and printer heads.

[0017] The method (4) of using white EL light backlighting and colorfilters in combination has a disadvantage that the utilizationefficiency of organic-EL light is so poor as to require a large powerconsumption.

[0018] Accordingly, as disclosed in Japanese Patent ApplicationLaid-open No. 11-8069, a process for producing an organic-EL devicemaking use of a photocurable acrylic resin is proposed, This process isa process in which a photosensitive resin composition prepared by addingan organic-EL material to a photocurable acrylic resin is coated on asubstrate to form a film, followed by exposure via a mask havingprescribed patterns and then development to form a photoemission layerand a hole transport layer and/or an electron transport layer in thatprescribed patterns.

[0019] According to this process, the layers can be formed in patternsin a simple manner for each color of RGB (red, green and blue). Theacrylic resin, however, may be affected by oxygen the atmosphere maycontain at the time of curing, so that the surface may cure withdifficulty. Especially in the production of organic-EL devices in whichphotoemission layers must be formed in thin films of about 100 nm thick,the rate of curing in air is so greatly low that the layers must beexposed in an inert atmosphere of argon, nitrogen or the like. This canbe an obstacle to the achievement of mass production of devices. Also,since a liquid is used as the photosensitive material, a gap must beprovided between the photosensitive material and the mask, and hence noprecise exposure can be effected.

SUMMARY OF THE INVENTION

[0020] An object of the present invention is to provide an organic-ELdevice production process by which fine-pattern photoemission layers canbe formed with ease and in a good precision, an organic-EL device whichcan be produced by that process, and an organic EL display system havingthat device.

[0021] To achieve the above object, the present invention provides aprocess for producing an organic-EL device; the process comprising thesteps of:

[0022] forming a film of at least one of;

[0023] (a) a high-molecular compound composition which contains ahigh-molecular compound having a divalent organic group represented bythe following Formula (7); and/or

[0024] (b) a high-molecular compound composition which contains i) ahigh-molecular compound having a divalent organic group represented bythe following Formula (8) and ii) a bisazide compound;

[0025] followed by exposure and then development to form a photoemissionlayer in a prescribed pattern.

[0026] wherein X is a divalent organic group containing at least one ofan allyl group (preferably having 2 to 10 carbon atoms), an aryl group(e g., a benzene ring residual group such as a phenyl group or aphenylene group), an alkylene group (preferably having 1 to 10 carbonatoms), an alkyl group (preferably having 1 to 10 carbon atoms), anamide group, an ester group, a nitrile group and a carbonyl group; andR⁷ to R⁹ are each a hydrogen atom or a monovalent organic groupcontaining at least one of an allyl group (preferably having 2 to 10carbon atoms), an aryl group (e.g., a benzene ring residual group suchas a phenyl group or a phenylene group), an alkylene group (preferablyhaving 1 to 10 carbon atoms), an alkyl group (preferably having 1 to 10carbon atoms), an amide group, an ester group, a nitrile group and acarbonyl group.

[0027] wherein W is a monovalent organic group containing at least oneof an allyl group (preferably having 2 to 10 carbon atoms), an arylgroup (e.g., a benzene ring residual group such as a phenyl group or aphenylene group), an alkylene group (preferably having 1 to 10 carbonatoms), an alkyl group (preferably having 1 to 10 carbon atoms), anamide group, an ester group, a nitrile group, a carbonyl group, acarbazole group and a fluorene group.

[0028] The present invention also provides an organic-EL device having aphotoemission layer containing a high-molecular compound having beencross-linked with a divalent organic group represented by the followingFormula (1) or (2), and an organic-EL display system having thatorganic-EL device. In the organic-EL device of the present invention,the photoemission layer may also have the function as a hole transportlayer or an electron transport layer.

[0029] In the formulas, X, Y and Z are each a divalent organic groupcontaining at least one of an allyl group (preferably having 2 to 10carbon atoms), an aryl group (e.g., a benzene ring residual group suchas a phenyl group or a phenylene group), an alkylene group (preferablyhaving 1 to 10 carbon atoms), an alkyl group (preferably having 1 to 10carbon atoms), an amide group, an ester group, a nitrile group and acarbonyl group. Also, R¹ to R⁶ are each a hydrogen atom or a monovalentorganic group containing at least one of an allyl group (preferablyhaving 2 to 10 carbon atoms), an aryl group (e.g., a benzene ringresidual group such as a phenyl group or a phenylene group), an alkylenegroup (preferably having 1 to 10 carbon atoms), an alkyl group(preferably having 1 to 10 carbon atoms), an amide group, an estergroup, a nitrile group and a carbonyl group.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] These and other features, objects and advantages of the presentinvention will become more apparent from the following description whentaken in conjunction with the accompanying drawings wherein:

[0031]FIG. 1 is a partial cross-sectional view presented to describe anexample of the structure of the organic-EL device of the presentinvention.

[0032]FIG. 2 Is a perspective view presented to describe an example ofthe organic-EL device of the present invention.

[0033]FIG. 3 is a partial cross-sectional view showing another exampleof the structure of the organic-EL device of the present invention.

[0034]FIG. 4 is a partial cross-sectional view showing still anotherexample of the structure of the organic-EL device of the presentinvention.

[0035]FIG. 5 is a partial cross-sectional view showing a further exampleof the structure of the organic-EL device of the present invention.

[0036]FIG. 6 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0037]FIG. 7 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0038]FIG. 8 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0039]FIG. 9 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0040]FIG. 10 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0041]FIG. 11 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0042]FIG. 12 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0043]FIG. 13 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0044]FIG. 14 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0045]FIG. 15 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0046]FIG. 16 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0047]FIG. 17 illustrates the function of a hole block layer,

[0048]FIG. 18 illustrates the function of a photoemissive hole transportlayer.

[0049]FIG. 19 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0050]FIG. 20 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0051]FIG. 21 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0052]FIG. 22 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0053]FIG. 23 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0054]FIG. 24 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0055]FIG. 25 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

[0056]FIGS. 26A to 26F illustrate an example of production steps for theorganic-EL device of the present invention.

[0057]FIGS. 27A to 27I illustrate another example of production stepsfor the organic-EL device of the present invention.

[0058]FIGS. 28A and 28B illustrate still another example of productionsteps for the organic-EL de vice of the present invention.

[0059]FIGS. 29A and 29B illustrate a further example of production stepsfor the organic-EL device of the present invention.

[0060]FIGS. 30A to 30C illustrate a still further example of productionsteps for the organic-EL device of the present invention.

[0061]FIGS. 31A and 31B illustrate a still further example of productionsteps for the organic-EL device of the present invention.

[0062]FIGS. 32A to 32G illustrate a still further example of productionsteps for the organic-EL device of the present invention,

[0063]FIGS. 33A and 33B illustrate a still further example of productionsteps for the organic-EL device of the present invention.

[0064]FIGS. 34A and 34B illustrate a still further example of productionsteps for the organic-EL device of the present invention.

[0065]FIGS. 35A to 35G illustrate a still further example of productionsteps for the organic-EL device of the present invention.

[0066]FIG. 36 is a diagrammatic view showing a high polymer cross-linkedwith photosensitive groups.

[0067]FIG. 37 is a diagrammatic view showing a high polymer and a lowpolymer both cross-linked with photosensitive groups.

[0068]FIG. 38 is a diagrammatic view showing a high polymer cross-linkedwith photosensitive groups, and fluorescent coloring matters.

[0069]FIG. 39 is a perspective view showing a glass substrate on whichstripe-shaped ITO electrodes have been formed.

[0070]FIG. 40 is a perspective view showing an exposure mask used inExamples.

[0071]FIG. 41 is a perspective view showing a substrate which is in astate where green-color photoemission layers have been formed thereon,

[0072]FIG. 42 is a cross-sectional view showing a substrate which is ina state where green-color photoemission layers have been formed thereon.

[0073]FIG. 43 is a cross-sectional view showing a substrate which is ina state where red-color and green-color photoemission layers have beenformed thereon.

[0074]FIG. 44 is a perspective view showing a substrate which is in astate where three-color photoemission layers have been formed thereon.

[0075]FIG. 45 is a cross-sectional view showing a substrate which is ina state where three-color photoemission layers have been formed thereon.

[0076]FIG. 46 is a perspective view of an organic-EL device produced inExample 1.

[0077]FIG. 47 is a cross-sectional view of the organic-EL deviceproduced in Example 1.

[0078]FIG. 48 is a perspective view of a substrate (with photoemissionlayers) standing before the cathode is formed in Example 8.

[0079]FIG. 49 is a cross-sectional view of the substrate (withphotoemission layers) standing before the cathode is formed in Example8.

[0080]FIG. 50 is a perspective view of an organic-EL device produced inExample 8.

[0081]FIG. 51 is a cross-sectional view of an organic-EL device producedin Example 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0082] In the present invention, a film is formed using a materialhaving already polymerized and standing as a high-molecular compound,and the film formed is exposed to cause it to undergo cross-linking tocure.

[0083] Hence, the film can be cured in air. Also, compositions used inthe film formation have a moderate viscosity that fine patterns can beformed with ease and in a good precision.

[0084] A. Photosensitive Composition Before Photo-crosslinking

[0085] (a) High-molecular Compound (Binder Polymer):

[0086] As to a high-molecular compound (binder polymer) having not beenphoto-crosslinked, there are no particular limitations on its backbonechain skeleton as long as it has a photo-crosslinkable group or iscapable of being photo-crosslinked with a photo-crosslinking agent. Forexample, polyvinyl resins, epoxy resins and phenolic resins may be used,There are also no particular limitations on its degree of polymerizationas long as a thin film of about 10 to 200 nm thick can be formed. It mayappropriately determined in accordance with necessary film propertiesand so forth, and may usually be from 10,000 to 2,000,000 asweight-average molecular weight.

[0087] It is desirable for the binder polymer to have at least onephoto-crosslinkable group of a cinnamoyl group, a cinnamylidene group, achalcone residual group, an isocoumarin residual group, a2,5-dimethoxystilbene residual group, a thymine residual group, astyrylpyridinium residual group, an α-phenylmaleinide residual group, ananthracene residual group and a 2-pyrone residual group. For example, itmay include those having repeating units as shown below. In thefollowing, letter symbol n represents any desired integer,

[0088] The binder polymer having such a photo-crosslinkable group mayinclude, e.g., polyvinyl resins having a repeating unit represented bythe following Formula (9). Thus, the binder polymer having aphoto-crosslinkable group in the molecule is preferred because it isunnecessary to mix any additional photo-crosslinking agent.

[0089] In Formula (9), X is a divalent organic group containing at leastone of an allyl group (preferably having 2 to 10 carbon atoms), an arylgroup (e.g., a benzene ring residual group such as a phenyl group or aphenylene group), an alkylene group (preferably having 1 to 10 carbonatoms), an alkyl group (preferably having 1 to 10 carbon atoms), anamide group, an ester group, a nitrile group and a carbonyl group; R⁷ toR⁹ are each a hydrogen atom or a monovalent organic group containing atleast one of an allyl group (preferably having 2 to 10 carbon atoms), anaryl group (e.g., a benzene ring residual group such as a phenyl groupor a phenylene group), an alkylene group (preferably having 1 to 10carbon atoms), an alkyl group (preferably having 1 to 10 carbon atoms),an amide group, an ester group, a nitrile group and a carbonyl group;and n is an integer.

[0090] A binder polymer having a fluorescent group and/or a carriertransport group in the molecule is also preferred because it isunnecessary to mix any additional fluorescent agent orcarrier-transporting agent. Such a functional binder polymer mayinclude, e.g., photo-crosslinkable hole-transporting high polymershaving a repeating unit represented by the following structuralformulas, Formulas (10) to (12), and a photo-crosslinkableelectron-transporting high polymer having a repeating unit representedby the following structural formula, Formula (13). Then, n is aninteger.

[0091] The binder polymer (having not been cross-linked) in the casewhen the photo-crosslinkable agent is used may preferably have an allylgroup (preferably having 2 to 10 carbon atoms), an aryl group (e.g., abenzene ring residual group such as a phenyl group or a phenylenegroup), an alkylene group (preferably having 1 to 10 carbon atoms), analkyl group (preferably having 1 to 10 carbon atoms), an amide group, anester group; a nitrile group, a carbonyl group, a carbazole group and/ora fluorene group. Such a high-molecular compound may include polyvinylresins represented by the following Formula (14).

[0092] In Formula (14), W is a monovalent organic group containing atleast one of an allyl group (preferably having 2 to 10 carbon atoms), anaryl group (e.g., a benzene ring residual group such as a phenyl groupor a phenylene group), an alkylene group (preferably having 1 to 10carbon atoms), an alkyl group (preferably having 1 to 10 carbon atoms),an amide group, an ester group, a nitrile group, a carbonyl group, acarbazole group and a fluorene group. Also, n represents an integer.

[0093] (b) Photo-crosslinking Agent:

[0094] Where the binder polymer does not have the abovephoto-crosslinkable group, it is desirable for the photosensitivecomposition to contain a photo-crosslinking agent. As thephoto-crosslinking agent, an aromatic bisazide is preferred.

[0095] The photo-crosslinking agent may preferably be mixed in an amountof from 5 to 50 parts by weight, and particularly preferably from 10 to30 parts by weight, based on 100 parts by weight of the binder polymer.If it is mixed in an amount less than 5 parts by weight, thephoto-crosslinking reaction may proceed insufficiently. If it is in anamount more than 50 parts by weight, insufficient photoemissionperformance or carrier transport performance may result.

[0096] (c) Functional Material:

[0097] The photosensitive composition used in the present invention maybe used to form any of photoemission layers, electron transport layersand hole transport layers.

[0098] Where the photosensitive composition is used to formphotoemission layers, a fluorescent coloring matter is mixed in thecomposition. This fluorescent coloring matter may preferably be mixed inan amount of from 0.1 to 10 parts by weight and particularly preferablyfrom 0.5 to 4 parts by weight, based on 100 parts by weight of thebinder polymer. If it is in an amount less than 0.1 part by weight, alow light emission intensity may result. If it is mixed in an amountmore than 10 parts by weight, extinction ascribable to concentration mayoccur to also provide a low light emission intensity.

[0099] Where the photosensitive composition is used to form holetransport layers or electron transport layers and when thehigh-molecular compound itself has neither hole transport properties norelectron transport properties, a hole-transporting agent or anelectron-transporting agent may be mixed in the composition, wherebysuch functions can be imparted to the layers. The hole-transportingagent or electron-transporting agent may preferably be mixed in anamount of from 5 to 120 parts by weight, and particularly preferablyfrom 50 to 80 parts by weight, based on 100 parts by weight of thebinder polymer. If it is mixed in an amount less than 5 parts by weight,the layer may have an insufficient carrier transport performance, If itis in an amount more than 120 parts by weight, the photosensitivecomposition may have insufficient film-forming properties,

[0100] (d) Photo-crosslinking Initiator:

[0101] In order to cause cross-linking reaction in a good efficiency bylight irradiation, a photo-crosslinking initiator may be mixed in thephotosensitive composition. As this photo-crosslinking initiator, usableare, e.g., benzoin, benzoin ethers, Michler's ketone, azobutyronitrileand 8-chlorothioxanthone. Many photoradical generators used in usualphotoresists are also usable as photo-crosslinking initiators.

[0102] The photo-crosslinking initiator may preferably be mixed in anamount of from 1 to 40 parts by weight, and particularly preferably from5 to 20 parts by weight, based on 100 parts by weight of the binderpolymer. If it is mixed in an amount less than 1 parts by weight, thephoto-crosslinking reaction may proceed insufficiently. If it is in anamount more than 40 parts by weight, the layer may have an insufficientphotoemission performance or carrier transport performance.

[0103] (e) Solvent:

[0104] There are no particular limitations on solvents as long as theyare capable of dissolving respective components mixed in thephotosensitive composition, such as the binder polymer having not beenphoto-crosslinked. Where the composition is coated by printing,preferred are N-methylpyrrolidone, γ-butyrolactone, dimethyl sulfoxide,dimethylformamide and mixed solvents of any of these, as havingrelatively high boiling points and superior dissolving power.

[0105] Based on 100 parts by weight of a solvent, the binder polymer maypreferably be mixed in an amount of from 1 to 30 parts by weight. Whenfilms are formed by either method of spin coating and printing, it isdifficult to form thin films if the binder polymer is mixed in an amountless than 1 part by weight. If it is in an amount more than 30 parts byweight, it is difficult to form thin films of 200 nm or smaller inthickness.

[0106] B. Curing Conditions

[0107] There are no particular limitations on a light source andwavelength used to effect photo-crosslinking. These may appropriately beso selected that the wavelength at which the photosensitive materialused is photosensitive and the wavelength of the light source may comeinto agreement and the irradiation can be made in an amount of lightthat is necessary and sufficient for the required degree of curing.

[0108] As the light source used to effect photo-crosslinking, usableare, e.g., high-pressure mercury lamps, halogen lamps and metal halidelamps.

[0109] As to the amount of exposure light for the photo-crosslinking,the photo-crosslinking can usually be effected at 50 to 5,000 mJ/cm²,and preferably at 500 to 3,000 mJ/cm². If the amount of exposure lightis smaller than 50 mJ/cm², too small cross-link density may result. Ifthe amount of exposure light is larger than 5,000 mJ/cm², side reactionsuch as reaction of fluorescent coloring matter with light may occur.Accordingly, it is desirable for its amount to be appropriatelyregulated in accordance with the types and concentrations of thephoto-crosslinking agent, photo-crosslinking initiator andphoto-crosslinkable group to be used,

[0110] C. High-molecular Compound (Binder Polymer) AfterPhoto-crosslinking

[0111] As to a high-molecular compound (binder polymer) having beenphoto-crosslinked, there are no particular limitations on its backbonechain skeleton as long as it has been cross-linked with thephoto-crosslinkable group or photo-crosslinking agent. For example,polyvinyl resins, epoxy resins and phenolic resins may be used. Thereare also no particular limitations on its degree of polymerization aslong as a thin film of about 10 to 200 nm thick can be formed. It mayappropriately determined in accordance with necessary film propertiesand so forth.

[0112] For the high-molecular compound (binder polymer) contained in thephotoemission layer of the present invention (and optionally theelectron transport layer and/or the hole transport layer), it isdesirable to have been cross-linked with at least onephoto-crosslinkable group of a cinnamoyl group, a cinnamylidene group, achalcone residual group, an isocoumarin residual group, a2,5-dimethoxystilbene residual group, a thymine residual group, astyrylpyridinium residual group, an α-phenylmaleimide residual group, ananthracene residual group and a 2-pyrrone residual group, or have beencross-linked with the photo-crosslinking agent (preferably an aromaticbisazide).

[0113] Such a binder polymer may include, e.g., polyvinyl resins havinga repeating unit represented by the following Formula (15) or (16).

[0114] In the formula, X, Y and Z are each a divalent organic groupcontaining at least one of an allyl group (preferably having 2 to 10carbon atoms), an aryl group (e.g., a benzene ring residual group suchas a phenyl group or a phenylene group), an alkylene group (preferablyhaving 1 to 10 carbon atoms), an alkyl group (preferably having 1 to 10carbon atoms), an amide group, an ester group, a nitrile group and acarbonyl group. Also, R¹ to R⁶ are each a hydrogen atom or a monovalentorganic group containing at least one of an allyl group (preferablyhaving 2 to 10 carbon atoms), an aryl group (e.g., a benzene ringresidual group such as a phenyl group or a phenylene group), an alkylenegroup (preferably having 1 to 10 carbon atoms), an alkyl group(preferably having 1 to 10 carbon atoms), an amide group, an estergroup, a nitrile group and a carbonyl group. Also, n represents aninteger.

[0115] As examples of the binder polymer used in the present invention,it may include, e.g., cross-linked polymers obtained byphoto-crosslinking any of polyvinyl carbazole type, polyalkylfluorenetype, polytriphenylamine type, soluble polyphenylenevinylene type,triazole type and oxathiazole type high polymers each having aphotosensitive group such as an azido group, a cinnamoyl group, acinnamylidene group, an acrylic group, a methacrylic group or a chalconegroup, as shown in FIG. 36, via this photosensitive group.

[0116] In the present invention, as the binder polymer, a high polymermay also be used which is obtained by, as shown in FIG. 37,photo-crosslinking a low polymer having the above-exemplifiedphotosensitive group in plurality, with a high polymer having thephotosensitive group in plurality.

[0117] A high polymer obtained by, as shown in FIG. 38,photo-crosslinking a fluorescent coloring matter having theabove-exemplified photosensitive group in plurality, with a high polymerhaving the photosensitive group in plurality may still also be used toform the photoemission layer.

[0118] In these materials, the linear high polymer cross-links uponirradiation by light to form networks, and become insoluble in solvents.

[0119] D. Photoemission layers

[0120] In the organic-EL device of the present invention, at least apart of photoemission layers comprises a cured product of thephotosensitive composition. More specifically, where the photoemissionlayers comprise blue-color photoemission layers (in a pattern) comprisedof a blue-color luminescent material, red-color photoemission layers (ina pattern) comprised of a red-color luminescent material and green-colorphotoemission layers (in a pattern) comprised of a green-colorluminescent material, at least one of the blue-color luminescentmaterial, the red-color luminescent material and the green-colorluminescent material contains the high-molecular compound having beenphoto-crosslinked with the organic group of Formula (1) or (2). Here,the photoemission layers (or a part thereof) may be so made as to servealso as at least one of the electron transport layer(s) and the holetransport layer(s). In the present invention, a photoemissive holetransport layer and a photoemissive electron transport layer are alsoincluded in the photoemission layers.

[0121] In the case when the photoemission layers are endowed with holetransport properties, a hole-transporting high-polymeric material orlow-polymeric material may be added. In the case when the photoemissionlayers are endowed with electron transport properties, anelectron-transporting high-polymeric material or low-polymeric materialmay be added. The low-polymeric material is incorporated into thenetworks of the high polymer having been photo-crosslinked, and hencedoes not dissolve easily in the subsequent steps. A high polymer mayalso be used which has a functional group having hole transportproperties or electron transport properties in the molecule.

[0122] In order to improve photoemission efficiency and photoemissioncolors, the photoemission layers may be doped with a fluorescentcoloring matter, As a method for the doping with a fluorescent coloringmatter, a coloring matter having a photosensitive group as a substituentmay be used. Alternatively, a coloring matter having no photosensitivegroup may merely be mixed in the photosensitive composition describedabove. Even when thus merely mixed, the fluorescent coloring matter thelayers have been doped with is incorporated into the networks of thehigh polymer having been photo-crosslinked, and hence does not dissolveeasily in the subsequent steps. As examples of such dopant fluorescentcoloring matter, it may include coumarin-type coloring matters,styryl-type coloring matters, merocyanine-type coloring matters,oxonol-type coloring matters, Nile Red, rubrene and perylene.

[0123] In the organic-EL device of the present invention, the device mayalso be so constructed that a hole transport layer containing afirst-color (e.g., blue-color) luminescent material is further providedand the photoemission layers comprise i) a hole block pattern comprisedof a hole-blocking material which inhibits the transport of holes, ii) afirst photoemission pattern comprised of a second-color (e.g.,red-color) luminescent material and iii) a second photoemission patterncomprised of a third-color (e.g., green-color) luminescent material. Inthis case, at least one of the hole-blocking material, the second-colorluminescent material and the third-color luminescent material containsthe high-molecular compound having been photo-crosslinked with theorganic group of Formula (1) or (2). Here, at least one of the firstphotoemission pattern and the second photoemission pattern may be somade as to serve also as the electron transport layer.

[0124] As materials for the first-color (e.g., blue-color) photoemissivehole transport layer, luminescent materials having a large band gap maybe used, such as cross-linked polyvinyl carbazole, polyalkylfluorene andpolytriphenylamine. Also, a hole-transporting low-molecular material anda blue-color luminescent low-molecular material may be used incombination in the photosensitive composition. These mixed low-molecularmaterials are incorporated into the networks of the cross-linked polymerhaving been photo-crosslinked, and hence do not dissolve easily in thesubsequent steps.

[0125] To form the hole block layer, a cross-linkable high polymer towhich molecules capable of exhibiting hole block performance have beenbonded may be used, or molecules capable of exhibiting hole blockperformance may be mixed in the cross-linkable high polymer.

[0126] The organic-EL device of the present invention may preferablyhave a hole transport layer containing a high polymer cross-linked withthe divalent organic group represented by the above Formula (1),provided that X and Y are each a divalent organic group represented byany of the following structural formulas, Formulas (3) to (5):

[0127] R¹, R², R⁴ and R⁵ are each a hydrogen atom; and R³ and R⁶ areeach a phenyl group.

[0128] This high-molecular compound has both the photo-curability andthe hole transport properties, and hence, especially when at least apart of the photoemission layers has also the hole transport properties,the compound is preferable for the formation of photoemission layershaving the hole transport properties (serving also the hole transportlayer).

[0129] The organic-EL device of the present invention may alsopreferably have an electron transport layer containing a high polymercross-linked with the divalent organic group represented by the aboveFormula (1), provided that X and Y are each a divalent organic grouprepresented by the following structural formula, Formula (6);

[0130] R¹, R²2, R⁴ and R⁵ are each a hydrogen atom; and R³ and R⁶ areeach a phenyl group.

[0131] This high-molecular compound has both the photo-curability andthe electron transport properties, and hence, especially when at least apart of the photoemission layers has also the electron transportproperties, the compound is preferable for the formation ofphotoemission layers having the electron transport properties (servingalso the electron transport layer).

[0132] E. Organic-EL Device

[0133] In the organic-EL device of the present invention, at least thephotoemission layer(s) comprise(s) a cured product of the photosensitivecomposition. In addition to the photoemission layer(s), one or both ofthe electron transport layer and the hole transport layer may comprise acured product of the photosensitive composition.

[0134] An example of the structure of the organic-EL device of thepresent invention is shown in FIG. 1. FIG. 1 is a partial illustrationof a structural cross section. As structure of the simplest organic-ELdevice, photoemission layers 3 are formed on anodes 2 comprised oftransparent conductive films formed on a glass substrate 1, and acathode 4 comprised of, e.g., a magnesium-silver alloy or analuminum-lithium alloy is further formed thereon. In this case, thephotoemission layers 3 have both the property of transporting holesinjected from the anodes 2 and the property of transporting electronsinjected from the cathode. The holes and electrons injected recombine inphotoemissive molecules in the interior of the photoemission layers 3,and fluorescent light is emitted in that course.

[0135] In an RGB full-color display device, the photoemission layers 3are, as shown in FIG. 1, constituted of red-color photoemission layers31, blue-color photoemission layers 32 and green-color photoemissionlayers 33. Also, in a multiple-color area color display device, therespective photoemission layers 31 to 33 are formed in patterns as shownin FIG. 2, for individual areas of logotypes and icons. In the presentinvention, these photoemission layers 31 to 33 may be constituted of thephoto-crosslinked high polymer or the the composition containing thephoto-crosslinked high polymer, whereby fine patterning can be made withease.

[0136] Another example of the structure of the organic-EL device of thepresent invention is shown in FIG. 3. In this example of structure,photoemission layers 3 and a hole transport layer 5 stand functionallyseparate from each other to provide an organic double-layer structure.More specifically, the hole transport layer 5 is provided between thephotoemission layers 3 and anodes 2. In this structure, thephotoemission layers 3 has both the photoemission properties and theelectron transport properties, but need not necessarily have theproperty of transporting holes. The holes injected from the anodes 2reach the photoemission layers 3 through the hole transport layer 5. Theelectrons injected from the cathode 4 are transported through theinterior of the photoemission layers 3. Thus, the holes and electronsinjected recombine in the interior of the photoemission layers 3, andthe energy thus produced causes photoemission. Incidentally, the holetransport layer 5, which is also an underlying layer of thephotoemission layers 3, is formed using a material containing a highpolymer insoluble in a solvent for a material solution used when thephotoemission layers 3 are formed. Such a high polymer may preferably bea cured product of a cross-linkable high polymer, like the cured productof the photosensitive composition used in the present invention, but amaterial containing an uncrosslinkable, solvent-insoluble high polymermay also be used.

[0137] Still another example of the structure of the organic-EL deviceof the present invention is shown in FIG. 4. In this example ofstructure, photoemission layers 3 and an electron transport layer 6stand functionally separate from each other to provide an organicdouble-layer structure. More specifically, the electron transport layer6 is provided between the photoemission layers 3 and the cathode 4. Inthis structure, the photoemission layers 3 has both the photoemissionproperties and the hole transport properties, but need not necessarilyhave the property of transporting electrons. The electrons injected fromthe cathode 4 are transported to the photoemission layers 3 through theelectron transport layer 6. The holes injected from the anodes 2 aretransported through the interior of the photoemission layers 3. Thus,the holes and electrons recombine in the interior of the photoemissionlayers 3, and the energy thus produced causes photoemission. Theelectron transport layer 6 may be formed using any of a low-molecularcompound, an uncrosslinkable polymer and a cross-linkable polymer, butit is better to use a cross-linked polymer like the cured product of thephotosensitive composition used in the present invention. This ispreferable because electron transport layer materials can have a highglass transition temperature (Tg) and the device can be improved inlong-term operation stability.

[0138] Thus, such function-separated structure in which thephotoemission layers 3 and the hole transport layer 5 or electrontransport layer 6 stand functionally separate enables a more improvementin photoemission efficiency,

[0139] A further example of the structure of the organic-EL device ofthe present invention is shown in FIG. 5. In this example of structure,photoemission layers 3, a hole transport layer 5 and an electrontransport layer 6 stand functionally separate from one another toprovide an organic triple-layer structure. More specifically, asubstrate 1, anodes 2, a hole transport layer 5, photoemission layers 3,an electron transport layer 6, a cathode 4 are superposed in this order.In this structure, the hole mobility and electron mobility in thephotoemission layers 3 need not necessarily be so much larger than thosein the corresponding transport layers.

[0140] Thus, such function-separated structure in which thephotoemission layers 3, and hole transport layer 5 and/or electrontransport layer 6 stand functionally separate enables a more improvementin photoemission efficiency.

[0141] The organic-EL device of the present invention may also beprovided with, as shown in FIG. 6, a hole injection layer 7 between theanodes 2 and the hole transport layer 5 so that the efficiency of holeinjection from the anodes 2 can be improved. The organic-EL device ofthe present invention may be provided with, as shown in FIG. 7, a bufferlayer 8 between the cathode 4 and the electron transport layer 6, or maybe provided with, as shown in FIG. 8, insulators 9 to separate adjoiningdots electrically so that any electric-current leak can be preventedfrom occurring between the adjoining dots.

[0142] As in a full-color display device of an RGB three-primary-colordot matrix type shown in FIG. 9, the device may also be constructed insuch a way that red-color photoemission layers 31 are so provided as torespectively cover anodes 2 in respect of {fraction (1/3)} (one third)among the anodes 2 to form red pixels, blue-color photoemission layers32 are so provided as to respectively cover anodes 2 in respect of other{fraction (1/3)} among the anodes 2 to form blue pixels, and green-colorphotoemission layers 33 are so provided as to respectively cover anodes2 in respect of the remaining {fraction (1/3)} among the anodes 2 toform green pixels at the areas not covered with the photoemission layers31 and 32. Incidentally, photoemission colors of the photoemissionlayers 31 to 33 are by no means limited to those shown here, and anydesired colors may be selected from among the three colors RGB.

[0143] In this example, the photoemission layer (green-colorphotoemission layers) 33 which covers the respective photoemissionlayers 31 and 32 need not necessarily be formed of the materialcontaining the photo-crosslinked polymer. The photoemission layer 33 hasthe property of electroluminescence and at the same time the property oftransporting holes and electrons, The photoemission layers 31 and 32each have the property of electroluminescence and at the same time theproperty of transporting holes, but need not necessarily have theproperty of transporting electrons. However, it is better for theselayers 31 and 32 also to have electron transport properties.

[0144] Into the photoemission layers 31 and 32, electrons are injectedthrough the photoemission layer 33. The holes and electrons injectedrecombine in molecules in the interior of the photoemission layers 3. Inthat course, fluorescent light is emitted. Compared with theconstruction shown in FIG. 1, the construction shown in FIG. 9 has anadvantage that it is unnecessary to form the photoemission layer 33 in apattern and hence the production steps can be fewer.

[0145] In the area color display device, the photoemission colors neednot be the RGB three primary colors. For example, pixels may be formedin five colors. In such a case, too, like the case shown in FIG. 9, onlyfour color photoemission layers may be formed in patterns and theremaining one color photoemission layer may be formed over the wholedisplay area. This enables formation of pixels in many colors through asmaller number of steps.

[0146] In the case when one photoemission layer 33 is so formed over thewhole as to cover other photoemission layers 31 and 32 in this way, likethe case described above, a hole transport layer 5 may also be providedbetween the photoemission layers 3 and the anodes 2 as shown in FIGS. 10and 12, or an electron transport layer 6 may be provided between thephotoemission layers 3 and the cathode 4 as shown in FIGS. 11 and 12,Also, as shown in FIG. 13, a hole injection layer 7 may be providedbetween the anodes 2 and the hole transport layer 5, and, as shown inFIG. 14, a buffer layer 8 may be provided between the cathode 4 and theelectron transport layer 6. Still also, as shown in FIG. 15, insulators9 may be provided between adjoining pixels.

[0147] As in a full-color display device of an RGB three-primary-colordot matrix type shown in FIG. 16, the device may also be constructed insuch a way that a blue-color photoemissive hole transport layer 50 is soprovided as to cover the anodes 2 and that red-color photoemissionlayers 31, green-color photoemission layers 33 and hole block layers 34are provided on the surface of this blue-color photoemissive holetransport layer 50 at its positions corresponding to the anodes 2. Likethe case of FIGS. 1 and 9 as described above, this construction isapplicable not only to the full-color display device of an RGBthree-primary-color dot matrix type but also to the multiple-color areacolor display device.

[0148] In the present organic-EL device, the holes injected from theanodes 2 are injected into the red-color photoemission layers 31 andgreen-color photoemission layers 33 through the blue-color photoemissivehole transport layer 50, and recombine with electrons in photoemissionatomic groups in the interior of the photoemission layers 31 and 33. Inthat course, red-color light and green-color light are emitted,

[0149] In contrast thereto, the emission of blue-color takes place inthe blue-color photoemissive hole transport layer 50. As shown in FIG.17, the holes injected from the anodes 2 are transported through theblue-color photoemissive hole transport layer 50 up to the vicinity ofthe interface between it and each hole block layer 34. However, the holeblock layer 34 has so great an ionization potential that the holes areby no means injected into the hole block layer 34. On the other hand,the electrons injected from the cathode 4 are injected into theblue-color photoemissive hole transport layer 50 through the electrontransport layer 6 and the hole block layer 34, The hole-electronrecombination takes place in the interior of the blue-colorphotoemissive hole transport layer 50, and blue-color light is emitted.

[0150] Here, in order for the hole block layers 34 to function in thisway, the layer must have an ionization potential of 6.0 eV or higher. Ifthe hole block layers 34 are not provided, as shown in FIG. 18 the holesinjected from the anodes 2 are injected into the electron transportlayer 6 through the blue-color photoemissive hole transport layer 50,but deactivate in the vicinity of the interface between them to becomeheat energy, because there is no photoemissive atomic group in theelectron transport layer 6.

[0151] The hole block layers 34 may be formed using a materialcontaining a phenanthrorine material represented by the followingFormula (17).

[0152] In the formula, R¹⁰ to R¹⁴ are each an alkyl group, alkenyl groupor alkoxyl group which is unsubstituted or has a substituent such as acyano group, a hydroxyl group, a nitro group, an amino group or adimethylamino group. Such molecules have a feature that they have agreater ionization potential than the blue-color photoemissive holetransport layer 50, thus the transport of holes is shut out here (FIG.17).

[0153] In the present invention, at least one of the red-colorphotoemission layers 31, the green-color photoemission layers 33 and thehole block 34 is comprised of a cured product of the photosensitivecomposition described above, and all of them may preferably be comprisedof such a cured product, Also, in this example, the blue-colorphotoemissive hole transport layer 50 serves as both a blue-colorphotoemission layer and a hole transport layer. However, any ofred-color and green-color photoemission layers may be so formed as toserve also as the hole transport layer.

[0154] In the construction in which the hole block layers 34 are used,too, like the case shown in FIG. 12, the photoemission layers 31 and thehole block layers 34 may be so provided that each of them covers eachcorresponding anode 2, and a green-color photoemission layer 33 a havingelectron transport properties may be so formed over the whole blue-colorphotoemissive hole transport layer 50 as to cover the red-colorphotoemission layers 31 and the hole block layers 34 (FIG. 19). Withsuch construction, compared with the example shown in FIG. 16, it isunnecessary to form the green-color photoemission layers 33 in a patternand hence the number of production steps can be cut down. Also, as shownin FIG. 20, a red-color photoemission layer 31 a having electrontransport properties may be so formed over the whole blue-colorphotoemissive hole transport layer 50 as to cover green-colorphotoemission layers 33 and hole block layers 34, Still also, theelectron transport layer 6 may be provided between such anelectron-transporting photoemission layer 31 a or 33 a and the cathode 4(FIGS. 21 and 22).

[0155] In the construction in which the hole block layers 34 areprovided, too, like the examples shown in FIGS. 1 and 9, a holeinjection layer 7 may be provided between the anodes 2 and theblue-color photoemissive hole transport layer 50 as shown in FIG. 23,and, as shown in FIG. 24, a buffer layer 8 may be provided between thecathode 4 and the electron transport layer 6. Still also, as shown inFIG. 25, insulators 9 may be provided between adjoining pixels.

[0156] F. Organic-EL Device Production Process

[0157] In the production process of the present invention, thephotoemission layers are formed using the photosensitive composition.The hole transport layer and/or the electron transport layer may also beformed using the photosensitive composition. When these layers areformed using the photosensitive composition, films (wet coatings) of thephotosensitive composition are first formed (by coating or the like),which are optionally dried, followed by exposure and development to forma prescribed pattern.

[0158] The films of the photosensitive composition may be formed by,e.g., spin coating or printing. Printing is preferred in view of anadvantage that the photosensitive composition can be used in a smallquantity. Where a coating film is formed by spin coating over the wholesurface of a substrate, in order to make mounting easy the film may beexposed to light through a photomask so that the external connectingterminal portions of a lead-out electrode are not irradiated by light,and thereafter such portions may preferably be removed by development.

[0159] Alternatively the photosensitive composition may previously bemolded into a self-supportive film, and this film may be stuck to thesurface of a substrate to provide the film thereon. Still alternatively,a thin film of the photosensitive composition may previously be formedon the surface of a support sheet, which is then stuck to the part wherethe film is to be formed, and thereafter the support sheet may be peeledto provide the film of the photosensitive composition.

[0160] When the hole transport layer and the electron transport layerare formed, a material composition may patternwise be printed on onlythe part from which the external connecting terminal portions of alead-out electrode have been removed, and thereafter the whole surfacemay be irradiated by light without use of any photomask to effectcross-linking and make the layer insoluble. Such a method promises ahigh productivity.

[0161] An example of the process for producing the organic-EL device ofthe present invention are described below with reference to FIGS. 26A to26F. First, on a glass substrate 1 on which transparent electrodes(anodes) 2 have been formed in a pattern, a photosensitive material (aphotoemission layer material solution containing a material having theproperty of causing cross-linking reaction upon light irradiation)capable of emitting light of a first color selected arbitrarily fromamong the three primary colors is coated to form a photoemissiort layermaterial coating 10 (FIG. 26A).

[0162] After the coating 10 is optionally dried, the coating film 10formed is irradiated by light through openings 20 of a photomask 11 toeffect exposure (FIG. 26B). In the photoemission layer material coatingfilm 10 thus exposed, crosslinking between molecular chains takes placeat a plurality of points in each molecule of the binder polymer, so thatthe exposed portions turn insoluble in the solvent. After the exposure,the unexposed portions are removed with the solvent, so that firstphotoemission layers 31 containing the cross-linked high polymer areformed in a pattern (FIG. 26C). The step of forming this pattern ofphotoemission layers is repeated twice, so that the three-colorphotoemission layers 31 to 33 are formed (FIGS. 26C to 26E). Here, thefirst-color photoemission layers 31 already formed are formed of thecross-linked high polymer, and hence by no means dissolve in anysolvents used in the second-color and third-color film formationprocessing.

[0163] Finally, a cathode 4 is formed to make up the RGBthree-primary-color dot matrix full-color display device which can makefull-color display. Incidentally, in the case of passive drive, thecathode is formed in the form of stripes falling at right angles withthe anodes. In the case of active drive using TFTs (thin-filmtransistors), its patterning is unnecessary.

[0164] Where the photoemission efficiency should have priority over thenumber of steps, as shown in FIGS. 27A to 27I a hole transport layerphotosensitive material film 51 is formed after the anodes 2 have beenformed and before a first luminescent material layer 10 is formed (FIG.27A), which is then optionally dried and then exposed (FIG. 27B) to formthe hole transport layer 5 (FIG. 27C). On its surface, the photoemissionlayers 31 to 33 and the cathode 4 may be formed in the same manner asthe steps shown in FIGS. 26A to 26F (FIGS. 27D to 27I).

[0165] The hole transport layer is required not to dissolve in anysolvents used in the formation of photoemission layers in the subsequentsteps. In this example, the cross-linkable high polymer isphoto-crosslinked by light irradiation to make the hole transport layerinsoluble. Incidentally, the photo-crosslinking need not necessarily becarried out when a solvent-insoluble high polymer such as a heat-curingresin is used in the hole transport layer. For example, when asolvent-insoluble high polymer such as polyphenylenevinylene is used inthe hole transport layer, the photo-crosslinking need not necessarily becarried out, and a polyphenylenevinylene precursor may be patternwiseprinted at display areas, followed by curing to form apolyphenylenevinylene film.

[0166] Where a film is formed over the whole surface of an underlyinglayer as in the case of the hole transport layer 5 in this example, itmay be formed by a coating method such as print coating (printing) orspin coating. In the case of print coating, the material is coated onthe substrate at its areas except the terminal portions and the wholesurface is irradiated by light to effect photo-crosslinking. In the caseof spin coating, the material is coated on the whole substrate surfaceand the surface is irradiated by light through a photomask, and coatingfilms at the terminal portions are not photo-crosslinked and removed bydevelopment.

[0167] On the other hand, where the number of steps should havepriority, the first and second photoemission layers 31 and 32 may beformed in the same manner as the steps shown in FIGS. 26A to 26D orFIGS. 27A to 27G.

[0168] Thereafter, as shown in FIG. 28A or FIG. 29A, a thirdphotoemission layer 33 may be so formed over the whole surface as tocover the photoemission layers 31 and 32 and the anodes 2 standinguncovered, and the cathode may be formed on the surface of this thirdphotoemission layer 33 (FIG. 28B or FIG. 29B).

[0169] A first method for forming this photoemission layer 33 is amethod in which a photoemission layer material solution (photosensitivecomposition) containing a material having the property of emittingthird-color light and the property of transporting electrons and holesand also having the property of causing photo-crosslinking reaction uponlight irradiation is coated to form a photoemission layer materialcoating, and, after the coating is optionally dried, the coating filmformed is irradiated by light only at the display areas via a photomaskto effect curing, followed by removal of unexposed areas at the terminalportions by using a solvent, to form the third photoemission layer 33containing the cross-linked high polymer.

[0170] A second method for forming the photoemission layer 33 is amethod in which the above photosensitive composition is coated by printcoating to form a coating only at the display area, and, after thecoating is optionally dried, the coating film formed is irradiated bylight over the whole surface to form the third photoemission layer 33containing the cross-linked high polymer.

[0171] A third method for forming the photoemission layer 33 is a methodin which a photoemission layer formation material containing a materialhaving the property of emitting third-color light and the property oftransporting electrons and holes is coated by print coating to form acoating only at the display area, and the coating is optionally dried toform the third photoemission layer 33 containing no cross-linked highpolymer.

[0172] A fourth method for forming the photoemission layer 33 is amethod in which a low-molecular-weight luminescent material containing amaterial having the property of emitting third-color light and theproperty of transporting electrons and holes is vacuum deposited to forma film only at the display area to form the third photoemission layer 33containing no cross-linked high polymer,

[0173] After the third photoemission layer 33 which cover the wholesurface has been thus formed (FIG. 30A), the electron transport layer 6may be formed on its surface (FIG. 30B), and thereafter the cathode 4may be formed (FIG. 30C). Alternatively, after the photoemission layers31 to 33 have been formed in the same manner as the steps shown in FIGS.26A to 26E, the electron transport layer 6 may be formed on its surface(FIG. 31A), and thereafter the cathode 4 may be formed (FIG. 31B).

[0174] In these cases, the step of forming the electron transport layer6 is the final step of forming organic layers, Accordingly, the electrontransport layer 6 need not necessarily be insoluble in the solvent, andhence a low-molecular-weight material and a linear high-molecular-weightmaterial may be used. Thus, there can be an advantage that materials maybe selected over a very wide range and materials having superiorphotoemission efficiency, lifetime and color purity can be selected. Inthe case when the low-molecular-weight material is used, the layer(s)is/are formed by vacuum deposition. In the case of the linearhigh-molecular-weight material, the layer(s) is/are formed by solutioncoating. However, the use of the photo-crosslinked high polymer which isthe cured product of the photosensitive composition is preferred to theuse of the low-molecular-weight material or linear high-molecular-weightmaterial, because the material can have a higher glass transitiontemperature (Tg) to bring about an improvement in long-term operationstability of the device.

[0175] In the case when the electron transport layer 6 is formed bycoating using a solution containing a high-molecular-weight material,the underlying photoemission layer 33 may preferably be formed by theabove first method. According to this method, the film is formed byexposure, using the material having the property of causingphoto-crosslinking reaction upon light irradiation, and hence thephotoemission layer 33 contains the cross-linked high polymer and standsinsoluble in the solvent. Thus, it by no means dissolves in the solventwhen the electron transport layer 6 is formed on its surface.

[0176] The organic-EL device having the blue-color photoemissive holetransport layer 50 and the hole block layers 34 can also be produced asshown in FIGS. 32A to 32G. More specifically, after the anodes 2 havebeen formed and before the first luminescent material film 10 is formed,a coating of the photosensitive composition for forming the blue-colorphotoemissive hole transport layer 50 is formed (FIG. 32A). After thecoating is optionally dried, the photoemission layers 31 and 33 areformed in the same manner as the steps shown in FIGS. 27D to 27G (FIGS.32B to 32F). Next, the hole block layers 34 are formed in a prescribedpattern at the pixel areas in the same mariner as the photoemissionlayers 31 and 33 (FIG. 32G), using a solution of a photosensitivecomposition for forming the hole block layers, containing aphotosensitive material having together the property of blocking thetransport of holes, the property of transporting electrons and theproperty of causing photo-crosslinking reaction upon light irradiation.Then the cathode 4 is formed thereon (FIG. 32G).

[0177] Methods for forming the blue-color photoemissive hole transportlayer 50 include the following two methods, which, when films arefurther formed on its surface, may appropriately selected depending onthe material used for its formation or film forming method (e.g.,whether or not a solvent which may attack the blue-color photoemissivehole transport layer 50).

[0178] A first method is a method in which a solution of a material forforming the blue-color photoemissive hole transport layer, containing amaterial having the property of emitting blue-light color and theproperty of transporting holes and also having the property of causingphoto-crosslinking reaction upon light irradiation is coated to form acoating of the material for forming the blue-color photoemissive holetransport layer, and, after the coating is optionally dried, the coatingfilm formed is irradiated by light only at the display areas via aphotomask to effect curing, followed by removal of unexposed areas atthe terminal portions by using a solvent, to form the blue-colorphotoemissive hole transport layer containing the cross-linked highpolymer.

[0179] A second method for forming the blue-color photoemissive holetransport layer 50 is a method in which a solution of a material forforming the blue-color photoemissive hole transport layer, containing amaterial having the property of emitting blue-light color and theproperty of transporting holes and also having the property of causingphoto-crosslinking reaction upon light irradiation is coated by printcoating to form a coating only at the display area, and, after thecoating is optionally dried, the coating film formed is irradiated bylight over the whole surface to form the blue-color photoemissive holetransport layer containing the cross-linked high polymer.

[0180] As the green-color photoemission layers 33, a green-colorphotoemissive electron transport layer 33 a may be formed as shown inFIGS. 33A and 33B, using a material having electron transportproperties, which is so formed as to cover the photoemission layers 31,the hole block layers 34 and the blue-color photoemissive hole transportlayer 50 standing uncovered (FIG. 33A), and the cathode 4 may be formedon its surface (FIG. 33B).

[0181] In this case, the step of forming the green-color photoemissiveelectron transport layer 33 a is the final step of forming organiclayers. Accordingly, the green-color photoemissive electron transportlayer 33 a need not necessarily be insoluble in the solvent, and hence alow-molecular-weight material and an uncrosslinkablehigh-molecular-weight material may be used, In the case when thelow-molecular-weight material is used, the layer can be formed by vacuumdeposition. In the case of the uncrosslinkable high-molecular-weightmaterial, the layer can be formed by solution coating. However, the useof the cross-linked high polymer is preferred to the use of thelow-molecular-weight material or uncrosslinkable high-molecular-weightmaterial, because the material can have a higher glass transitiontemperature (Tg) to bring about an improvement in long-term operationstability of the device.

[0182] The organic-EL device shown in FIG. 22, the photoemission layers3 of which comprise the blue-color photoemissive hole transport layer50, the green-color photoemission layers 33, the hole block layers 34and the red-color photoemissive electron transport layer 31 a can alsobe produced by a like process but by appropriately selecting luminescentmaterials.

[0183] Where the electron transport layer 6 is formed between thegreen-color photoemissive electron transport layer 33 a and the cathode4 in order to improve electron transport performance, the green-colorphotoemissive hole transport layer 33 a may be formed in the same manneras the steps shown in FIGS. 32A to 32E and FIG. 33A, Thereafter, theelectron transport layer 6 may be formed as shown in FIG. 34A, on thesurfaces of pixel areas over the whole display region, and the cathode 4may be formed as shown in FIG. 34B.

[0184] As described above, the process for producing the RGB full-colororganic-EL device of the present invention is a process in which atleast part of the photoemission layers is formed in a pattern byphotolithographic processing. Thus, RGB patterns can be formed by asimple process in a better precision than conventional low-polymer maskvacuum deposition and ink-jet printing.

[0185] The foregoing examples concern processes used when the full-colordisplay devices having RGB three-primary-color photoemission layerpatterns are produced. These processes are applicable to themultiple-color area color display device as long as the patterns ofphotoemission layers are changed. An example of a process by which amultiple-color area color display organic-EL device having RGBthree-primary-color photoemission layer logotypes is shown in FIGS. 35Ato 35G.

[0186] First, on a glass substrate 1 on which transparent electrodes(anodes) 2 have been formed in a pattern, a first-color photosensitivecomposition (a photoemission layer material solution containing amaterial capable of emitting light of a first color and also having theproperty of causing cross-linking reaction upon light irradiation) iscoated to form a photoemission layer material coating 40 (FIG. 35A).After the coating 40 is optionally dried, the coating film formed isirradiated by light via a photomask to effect exposure. In thephotoemission layer material coating film 40 thus exposed, cross-linkingbetween molecular chains takes place at a plurality of points in eachmolecule of the binder polymer, so that the exposed portions turninsoluble in the solvent. After the exposure, the unexposed portions areremoved with the solvent, so that a photoemission layer 15 containingthe cross-linked high polymer is formed in a pattern (FIG. 35B).

[0187] The like procedure is repeated to form second- to fourth-colorphotoemission layers 16 to 18 are sequentially formed in patterns (FIGS.35C to 35F). Here, the photoemission layer patterns already formed havebeen made insoluble by means of the cross-linked high polymer, and henceby no means dissolve in any solvents used in the second-color andfollowing film formation processing.

[0188] Finally, a cathode 4 is formed to make up the organic-EL devicewhich can make multiple-color area color display In the multiple-colorarea color display device, the photosensitive composition maypatternwise be printed when the photoemission layer patterns 15 to 18are formed. Such pattern printing enables whole-area exposure withoutmasking to effect curing, and hence the step of development isunnecessary, making it possible to produce the device more simply thanthe above method. This method is very effective when relatively roughpatterns are formed.

[0189] As described above, the present invention enables simpleproduction of organic-EL devices which can make three-primary-color dotmatrix full-color display or multiple-color area color display device.Incidentally, described in the foregoing examples are organic-EL devicesfor color display, but monochromatic display organic-EL devices can alsobe produced with ease by the process according to the present inventionand are embraced in the present invention. Also, organic-EL devicesinvolving both the dot matrix display and the area display (such aslogotypes) can be produced with ease by the process according to thepresent invention.

[0190] The organic-EL device of the present invention and the processfor its production are described below in greater detail by givingExamples. The present invention is by no means limited to these Examplesonly.

EXAMPLE 1

[0191] A first working example is described below.

[0192] On the whole surface of one of the both sides of a glasssubstrate of 0.7 mm in thickness and 25×25 mm in size, an ITO (indiumtin oxide) film having a thickness of 200 nm and a sheet resistance of15 W was formed by EB (electron beam) vacuum deposition. The ITO filmthus formed was subjected to etching to form, as the anode, nine stripes19 as shown in FIG. 39, each having a width of 1.0 mm and a length of 25mm and at intervals of 1.0 mm.

[0193] Next, after the surface of this substrate with the anode wassubjected to oxygen plasma treatment, a photosensitive composition forforming green-color photoemission layers was spin-coated at 3,000 rpm,followed by drying at 80° C. for 30 minutes to form a film of thephotosensitive composition Here, the photosensitive composition forforming green-color photoemission layers comprises 0.55 g of a binderpolymer, 0.05 g of coumarin-6 represented by the structural formula(18), 0.35 g of an oxadiazole derivative represented by the structuralformula (19), 0.1 g of Michler's ketone represented by the structuralformula (20) and 10 g of N-methylpyrrolidone.

[0194] In the present example, used as the binder polymer was a randomcopolymer having a repeating unit represented by the structural formula(21) and a repeating unit represented by the structural formula (22),i.e., polyvinyl carbazole part of a carbazole group in the molecule ofwhich has been substituted with a cinnamoyl group. In the formulas (21)and (22), n and m are each an integer of 1 or more, where polymerizationratio n:m is 1.1 and weight-average molecular weight is 160,000. Thiscopolymer is hereinafter simply called a polyvinyl carbazole derivative.

[0195] This polyvinyl carbazole derivative transports holes injectedfrom the anode. Also, the oxadiazole derivative transports electronsinjected from the cathode. The coumarin-6 is a compound which causes theinjected holes and electrons to recombine to effect green-colorphotoemission.

[0196] Next, the photosensitive composition film thus formed was exposedto ultraviolet radiation via photomask 21 (FIG. 40) provided with threestripes of openings 20 each having a width of 2.0 mm and a length of 12mm and at intervals of 4.0 mm. Here, the photomask 21 was so disposedthat the center line of each ITO stripe 19 come into agreement with thecenter line of each photomask opening 20. As a light source, ahigh-pressure mercury lamp having an exposure illumination of 45 mW/cm²was used, by means of which the exposure was made for 60 minutes so asto be in a total exposure dose of 2,700 mJ. Subsequently, this wasimmersed in N-methylpyrrolidone for 1 minute to remove unexposed-areafilms by development, followed by rinsing with acetone and thereafterdrying at 80° C. for 30 minutes.

[0197] Through these steps, green-color photoemission layer stripes 33were formed as shown in FIGS. 41 and 42. Incidentally, FIG. 42 is across-sectional view along the line A-A′ in FIG. 41. The photoemissionlayers 33 thus formed have a structure wherein the coumarin-6 and theoxadiazole derivative are confined in the networks of the polyvinylcarbazole cross-linked with cinnamoyl groups, and hence do not dissolvein any solvent used in the following subsequent step.

[0198] Next, a photosensitive composition for forming red-colorphotoemission layers, comprising 0.55 g of the polyvinyl carbazolederivative, 0.35 g of the oxadiazole derivative, 0.15 g of an aromaticbisazide represented by the structural formula (23), 0.05 g of Nile Redrepresented by the structural formula (24) and 10 g ofN-methylpyrrolidone, was spin-coated at 3,000 rpm. Nile Red is afluorescent coloring matter dopant for red-color photoemission.

[0199] The photomask used to form the green-color photoemission layerstripes was disposed at a position moved in parallel by 2 mm from thatat the time of the formation of the green-color photoemission layerstripes, and exposure and development were carried out in the samemanner as the step of forming the green-color photoemission layers toform red-color photoemission layers 31 (FIG. 43). Like the case of thegreen-color photoemission layers, the red-color photoemission layers 31thus formed have a structure wherein Nile Red and the oxadiazolederivative are confined in the networks of the polyvinyl carbazolecross-linked with cinnamoyl groups, and hence do not dissolve in anysolvent used in the following subsequent step.

[0200] Next, using a photosensitive composition for forming blue-colorphotoemission layers, comprising 0.55 g of the polyvinyl carbazolederivative, 0.35 g of the oxadiazole derivative, 0.02 g of1,1,4,4-tetraphenyl-1,3-butadiene represented by the structural formula(25), 0.1 g of Michler's ketone and 10 g of N-methylpyrrolidone, thecoating, exposure and development were carried out in the same manner asthe above steps to form blue-color photoemission layers 32 (FIG. 44).

[0201] The blue-color photoemission layers 32 thus formed have astructure wherein the 1,1,4,4-tetraphenyl-1,3-butadiene and theoxadiazole derivative are confined in the networks of the polyvinylcarbazole cross-linked with cinnamoyl groups.

[0202] The polyvinyl carbazole derivative transports holes injected fromthe anode, and the oxadiazole derivative transports electrons injectedfrom the cathode. The 1,1,4,4-tetraphenyl-1,3-butadiene is a compoundwhich causes the injected holes and electrons to recombine to effectblue-color photoemission.

[0203] Thus, as shown in FIGS. 44 and 45, a panel having stripe patterns31 to 33 consisting of green, red and blue three colors was obtained.FIG. 45 is a cross-sectional view along the line B-B′ in FIG. 44. Thephotoemission layers 31 to 33 were each in a thickness of 100 nm.

[0204] Next, using a vacuum deposition mask having an opening of 16×25mm in size, a 200 nm thick cathode 4 comprised of Mg/Ag (1/10) wasformed by vacuum co-deposition.

[0205] The organic-EL device thus obtained is shown in FIGS. 46 and 47.

[0206]FIG. 4′ is a cross-sectional view along the line C-C′ in FIG. 46.Setting the ITO as the anodes 2 and the Mg/Ag as the cathode 4, avoltage of 10 V was applied to this device by means of a DC powersource, whereupon the green, red and blue three-color light was emittedin stripes.

EXAMPLE 2

[0207] A second working example is described below.

[0208] The same glass substrate with an ITO pattern as that used inExample 1 was subjected to oxygen plasma treatment. Thereafter, acoating of a photosensitive composition for forming a hole transportlayer was formed on the whole pixel-areas by flexographic printing,followed by drying at 80° C. for 30 minutes to form a film of thephotosensitive composition. Here, in the present example, a compositioncomprising 0.35 g of the polyvinyl carbazole derivative, 0,1 g ofMichler's ketone and 10 g of N-methylpyrrolidone was used as thephotosensitive composition for forming the hole transport layer.

[0209] Next, the whole surface of the coating film formed was exposed toultraviolet radiation for 60 seconds, using a high-pressure mercury lamphaving an exposure illumination of 45 mW/cm². Here, the total exposuredose was 2,700 mJ. Thus, a hole transport layer having a thickness of 50nm was formed.

[0210] Next, green, red and blue three-color stripe-shaped photoemissionlayers 31 to 33 and the cathode 4 were formed in the same manner as inExample 1 to obtain an organic-EL device. A voltage of 10 V was appliedto this device, whereupon the green, red and blue three-color light wasseen to be emitted in stripes.

EXAMPLE 3

[0211] A third working example is described below.

[0212] The same glass substrate with an ITO pattern as that used inExample 1 was subjected to oxygen plasma treatment. Thereafter, using asolution comprising 0.3 g of a polyphenylenevinylene precursorrepresented by the structural formula (26) and 10 g of butyl cellosolve, a coating of was formed on the pixel areas by flexographicprinting.

[0213] Next, this coating was subjected to heat treatment at 250° C. for1 hour in an atmosphere of nitrogen to convert it into a hole transportlayer comprised of polyphenylenevinylene. The layer was in a thicknessof 50 nm. Subsequently, green, red and blue three-color stripe-shapedphotoemission layers 31 to 33 and the cathode 4 were formed in the samemanner as in Example 1 to obtain an organic-EL device. A voltage of 10 Vwas applied to this device, whereupon the green, red and bluethree-color light was emitted in stripes.

EXAMPLE 4

[0214] A fourth working example is described below.

[0215] In the present example, a solution comprising 0.55 g of thepolyvinyl carbazole (weight-average molecular weight: 1,100,000)represented by the structural formula (22) set out previously, 0.15 g ofthe aromatic bisazide represented by the structural formula (23), 0.05 gof coumarin-6, 0.35 g of the oxadiazole derivative represented by thestructural formula (19) and 10 g of N-metylpyrrolidone was used as thephotosensitive composition for forming green-color photoemission layers.

[0216] As the photosensitive composition for forming red-colorphotoemission layers, a solution comprising 0.55 g of the polyvinylcarbazole represented by the structural formula (22), 0.15 g of thearomatic bisazide represented by the structural formula (23), 0.05 g ofNile Red, 0.35 g of the oxadiazole derivative represented by thestructural formula (19) and 10 g of N-methylpyrrolidone was also used.

[0217] As the photosensitive composition for forming blue-colorphotoemission layers, a solution comprising 0.55 g of the polyvinylcarbazole represented by the structural formula (22), 0.15 g of thearomatic bisazide represented by the structural formula (23), 0.02 g of1,1,4,4-tetraphenyl-1,3-butadiene, 0.35 g of the oxadiazole derivativerepresented by the structural formula (19) and 10 g ofN-methylpyrrolidone was used.

[0218] The procedure of Example 1 was repeated except for using thesecompositions for forming photoemission layers, to produce an organic-ELdevice in which the anodes 2, the green, red and blue three-colorstripe-shaped photoemission layers 31 to 33 and the cathode 4 weresuperposed on the glass substrate 1. A voltage of 10 V was applied tothe device thus obtained, whereupon the green, red and blue three-colorlight was emitted in stripes,

EXAMPLE 5

[0219] A fifth working example is described below,

[0220] The hole transport layer comprised of a cross-linked high polymerand the stripe-shaped three-primary-color photoemission layers comprisedof a cross-linked high polymer, a coloring matter, anelectron-transporting material and a hole-transporting material wereformed in the same manner as in Example 2.

[0221] Next, a photosensitive composition for forming an electrontransport layer, comprising 0.6 g of polymethyl methacrylate(weight-average molecular weight: 230,000), 0.35 g of the aromaticbisazide represented by the structural formula (23), 0.3 g oftris(8-quinolinolato)aluminum represented by the structural formula (27)and 10 g of N-methylpyrrolidone, was patternwise printed by flexographicprinting at the center area of the substrate, followed by drying to forman electron transport layer with a thickness of 30 nm,

[0222] Next, the cathode was formed in the same manner as in Example 1to obtain an organic-EL device. A voltage of 10 V was applied to thisdevice, whereupon the green, red and blue three-color light was emittedin stripes.

EXAMPLE 6

[0223] A sixth working example is described below.

[0224] The hole transport layer comprised of a cross-linked high polymerand the stripe-shaped three-primary-color photoemission layers comprisedof a cross-linked high polymer, a coloring matter, anelectron-transporting material and a hole-transporting material wereformed in the same manner as in Example 2.

[0225] Next, an electron transport layer with a thickness of 30 nm,consisting of a thin film of the tris(8-quinolinolato)aluminum, wasformed by vacuum deposition, and thereafter the cathode was formed inthe same manner as in Example 1 to obtain an organic-EL device. Avoltage of 10 V was applied to this device, whereupon the green, red andblue three-color light was emitted in stripes.

EXAMPLE 7

[0226] A seventh working example is described below.

[0227] On the whole surface of a glass substrate of 0.7 mm in thicknessand 25×25 mm in size, an ITO film having a thickness of 200 nm and asheet resistance of 15 W was formed by EB vacuum deposition. The ITOfilm thus formed was subjected to patterning in logotypes as the anodeas shown in FIG. 35A.

[0228] After the surface of this substrate with the anode was subjectedto oxygen plasma treatment, the same photosensitive composition 40 forforming green-color photoemission layers as that in Example 1 wasspin-coated at 3,000 rpm, followed by drying at 80° C. for 30 minutes toform a film. Then, the film was exposed to ultraviolet radiation at itspart involving the letter “O” and letter “D” via a photomask, followedby development to form green-color photoemission layers. Then, the samephotosensitive composition for forming red-color photoemission layers asthat in Example 1 was also spin-coated at 3,000 rpm, followed by dryingat 80° C. for 30 minutes to form a film. Thereafter, the film wasexposed to ultraviolet radiation at its part involving the letter “L”via a photomask, followed by development to form a red-colorphotoemission layer.

[0229] Subsequently, the same photosensitive composition for formingblue-color photoemission layers as that in Example 1 was spin-coated at3,000 rpm, followed by drying at 80° C. for 30 minutes to form a film.

[0230] Thereafter, the film was exposed to ultraviolet radiation at itspart involving the letter “E” via a photomask, followed by developmentto form a blue-color photoemission layer.

[0231] As the light source used when the photosensitive compositionfilms were exposed, a high-pressure mercury lamp having an exposureillumination of 45 mW/cm² was used, by means of which the exposure wasmade for 60 minutes so as to be in a total exposure dose of 4700 mJ.Also, as to the development, the films were immersed inN-methylpyrrolidone for 1 minute to remove unexposed-area films,followed by rinsing with acetone and thereafter drying at 80° C. for 30minutes.

[0232] Next, on the part involving this logotype, the samephotosensitive composition for forming an electron transport layer asthat in Example 6 was patternwise printed by flexographic printing,followed by drying at 80° C. for 30 minutes to form an electrontransport layer with a thickness of 30 nm. Subsequently, using a vacuumdeposition mask, a 200 nm thick cathode 4 consisting of Mg/Ag (1/10) wasformed by vacuum co-deposition to obtain an organic-EL device.

[0233] To this device, setting the ITO as the anode and the Mg/Ag as thecathode, a voltage of 10 V was applied by means of a DC power source,whereupon the layers at the part of the letter “O” and letter “D”emitted light in green color, the letter “L” in red color, and theletter “E” in blue color.

EXAMPLE 8

[0234] An eighth working example is described below.

[0235] An organic-EL device was produced in the same manner as inExample 1 except that the green-color photoemission layers 33 andred-color photoemission layers 31 were each formed as shown in FIG. 48in a thickness of 50 nm, and the blue-color photoemission layer 32 in athickness of 100 nm. Also, in the exposure to form the blue-colorphotoemission layers 32, a photomask made of quartz and having anopening of 16×25 mm was used. Thus, as shown in FIG. 48, the blue-colorphotoemission layer 32 was so formed as to cover the green-colorphotoemission layers 33 and red-color photoemission layers 31. Across-sectional view along the line D-D′ in FIG. 48 is shown in FIG. 49.

[0236] The cathode 4 was formed in the same manner as in Example 1 toobtain an organic-EL device shown in FIG. 50. A cross-sectional viewalong the line E-E′ in FIG. 50 is shown in FIG. 51. To this device,setting the ITO as the anode and the Mg/Ag as the cathode, a voltage of10 V was applied by means of a DC power source, whereupon the green, redand blue three-color light was emitted in stripes.

EXAMPLE 9

[0237] A ninth working example is described below.

[0238] An organic-EL device was produced in the same manner as inExample 2 except that the respective photoemission layers 31 to 33 wereformed in the same manner as in Example 8 in the like layer thicknessand using the like exposure mask for the blue-color photoemission layer.

[0239] To the device thus obtained, a voltage of 10 V was applied,whereupon the green, red and blue three-color light was emitted instripes.

EXAMPLE 10

[0240] A tenth working example is described below.

[0241] An organic-EL device was produced in the same manner as inExample 3 except that the respective photoemission layers 31 to 33 wereformed in the same manner as in Example 8 in the like layer thicknessand using the like exposure mask for the blue-color photoemission layer.

[0242] To the device thus obtained, a voltage of 10 V was applied,whereupon the green, red and blue three-color layers emitted light instripes.

EXAMPLE 11

[0243] An eleventh working example is described below.

[0244] An organic-EL device was produced in the same manner as inExample 4 except that the respective photoemission layers 31 to 33 wereformed in the same manner as in Example 8 in the like layer thicknessand using the like exposure mask for the blue-color photoemission layer.To the device thus obtained, a voltage of 10 V was applied, whereuponthe green, red and blue three-color light was emitted in stripes.

EXAMPLE 12

[0245] A twelfth working example is described below.

[0246] An organic-EL device was produced in the same manner as inExample 5 except that the respective photoemission layers 31 to 33 wereformed in the same manner as in Example 8 in the like layer thicknessand using the like exposure mask for the blue-color photoemission layerand the tris(8-quinolinolato)aluminum was replaced with 0.35 g of theoxadiazole derivative represented by the structural formula (19). To thedevice thus obtained, a voltage of 10 V was applied, whereupon thegreen, red and blue three-color light was emitted in stripes.

EXAMPLE 13

[0247] A thirteenth working example is described below.

[0248] An organic-EL device was produced in the same manner as inExample 6 except that the respective photoemission layers 31 to 33 wereformed in the same manner as in Example 8 in the like layer thicknessand using the like exposure mask for the blue-color photoemission layer.To the device thus obtained, a voltage of 10 V was applied, whereuponthe green, red and blue three-color light was emitted in stripes.

EXAMPLE 14

[0249] A fourteenth working example is described below with reference toFIGS. 32A to 32G.

[0250] The same glass substrate with ITO stripes as that used in Example1 was subjected to oxygen plasma treatment. Thereafter, a photosensitivecomposition for forming a blue-color photoemissive hole transport layer,comprising 0.35 g of the polyvinyl carbazole derivative, 0.05 g ofMichler's ketone and 10 g of N-methylpyrrolidone, was spin-coated at3,000 rpm, followed by drying at 80° C. for 30 minutes to form a coatingfilm.

[0251] Then, the coating film formed was exposed to ultravioletradiation via a photomask made of quartz and having an opening of 16×25mm was used. As a light source, a high-pressure mercury lamp having anexposure illumination of 45 mW/cm² was used, by means of which theexposure was made for 60 minutes so as to be in a total exposure dose of2,700 mJ. Next, this was immersed in N-methylpyrrolidone for 1 minute toremove unexposed-area films by development, followed by rinsing withacetone and thereafter drying at 80° C. for 30 minutes. Thus, theblue-color photoemissive hole transport layer 50 having a layerthickness of 80 nm was formed on the whole surface of pixel-formingregion. (FIG. 32A).

[0252] The polyvinyl carbazole derivative transports holes injected fromthe anode and at the same time contributes to blue-color photoemissionin the course of recombination of electrons and holes. The blue-colorphotoemissive hole transport layer 50 thus formed has a structurewherein the polyvinyl carbazole derivative has cross-linked, and hencedoes not dissolve in any solvent used in the following subsequent step.

[0253] On the surface of this blue-color photoemissive hole transportlayer 50, red-color photoemission layers 31 each having a layerthickness of 80 nm were formed in the same manner as in Example 1 (FIGS.32B to 32D), using a photosensitive composition for forming red-colorphotoemission layers, comprising 0.35 g of the polyvinyl carbazolederivative, 0.55 g of the same oxadiazole derivative as that used inExample 1, 0.05 g of Nile Red, 0.05 g of Michler's ketone and 10 g ofN-methylpyrrolidone.

[0254] Next, green-color photoemission layers 33 each having a layerthickness of 80 nm were formed in the same manner as in Example 1 (FIG.32E), using a photosensitive composition for forming green-colorphotoemission layers, comprising 0.35 g of the polyvinyl carbazolederivative, 0.55 g of the same oxadiazole derivative as that used inExample 1, 0.05 g of coumarin-6, 0.05 g of Michler's ketone and 10 g ofN-methylpyrrolidone.

[0255] Subsequently, a photosensitive composition for forming hole blocklayers, comprising 0.5 g of polyvinyl cinnamate represented by thestructural formula (28), 0.15 g of bathocuproin represented by thestructural formula (29), 0.25 g of the same oxadiazole derivative asthat in Example 1, 0.1 g g of Michler's ketone and 10 g ofN-methylpyrrolidone, was spin-coated at 3,000 rpm on the blue-colorphotoemissive hole transport layer 50 on which the red-color andgreen-color hole block layers had been formed, followed by drying at 80°C. for 30 minutes, The oxadiazole derivative transports electronsinjected from the cathode, and the bathocuproin is used to shut out thetransport of holes.

[0256] In the formula (28), n is an integer.

[0257] The photomask was disposed at a position moved in parallel by 2mm from the position at which the green-color photoemission layers wereformed, and exposure and development were carried out in the same manneras the step of forming the above photoemission layers to form hole blocklayers 34 each having a layer thickness of 80 nm (FIG. 32F).

[0258] Like the case of the green-color photoemission layers, the holeblock layers 34 thus formed have a structure wherein bathocuproin andthe oxadiazole derivative are confined in the networks of the polyvinylcarbazole cross-linked with cinnamoyl groups, and hence do not dissolvein any solvent used in the following subsequent step.

[0259] Next, a photosensitive composition for forming an electrontransport layer, comprising 0.6 g of polymethyl methacrylate representedby the structural formula (30), 0.15 g and 0.35 g of the same aromaticbisazide and oxadiazole derivative, respectively, as those in Example 1and 10 g of N-methylpyrrolidone, was patternwise printed by flexographicprinting at the center area of the substrate, followed by exposure toultraviolet radiation over the whole surface under the same exposureconditions as the case of the above photoemission layers, to form anelectron transport layer 6 with a thickness of 50 nm.

[0260] In the formula (30), n is an integer.

[0261] Finally, the cathode 4 was formed in the same manner as inExample 1 to obtain an organic-EL device shown in FIG. 32G. To thisdevice, setting the ITO as the anode and the Mg/Ag as the cathode, avoltage of 10 V was applied by means of a DC power source, whereupon thegreen, red and blue three-color light was emitted in stripes.

EXAMPLE 15

[0262] A fifteenth working example is described below.

[0263] The ITO electrodes, blue-color photoemissive hole transportlayer, red-color photoemission layers, green-color photoemission layers,hole block layers, electron transport layer and cathode were formed onthe surface of the glass substrate to obtain an organic-EL device in thesame manner as in Example 14 except that, in the photosensitivecomposition for forming the blue-color photoemissive hole transportlayer, 0,02 g of 1,1,4,4-tetraphenyl-1,3-butadiene was mixed and theMichler's ketone was mixed in an amount of 0.1 g.

[0264] To this device, setting the ITO as the anode and the Mg/Ag as thecathode, a voltage of 10 V was applied by means of a DC power source,whereupon the green, red and blue three-color light was emitted instripes.

EXAMPLE 16

[0265] A sixteenth working example is described below.

[0266] The ITO electrodes, blue-color photoemissive hole transportlayer, green-color photoemission layers, red-color photoemission layers,hole block layers, electron transport layer and cathode were formed onthe surface of the glass substrate to obtain an organic-EL device in thesame manner as in Example 14 except that a solution comprising 0.6 g ofpolymethyl methacrylate, 0.35 g of the same oxadiazole derivative asthat used in Example 1 and 10 g of N-methylpyrrolidone was used as thephotosensitive composition for forming the electron transport layer.

[0267] To the device thus obtained, setting the ITO as the anode and theMg/Ag as the cathode, a voltage of 10 V was applied by means of a DCpower source, whereupon the green, red and blue three-color light wasemitted in stripes.

EXAMPLE 17

[0268] A seventeenth working example is described below.

[0269] The ITO electrodes, blue-color photoemissive hole transportlayer, green-color photoemission layers, red-color photoemission layers,hole block layers, electron transport layer and cathode were formed onthe surface of the glass substrate to obtain an organic-EL device in thesame manner as in Example 14 except that the electron transport layer(thickness: 50 nm) was formed using a vacuum deposition mask having anopening of 16×25 mm was used and formed by vacuum deposition oftris(8-quinolinolato)aluminum.

[0270] To the device thus obtained, setting the ITO as the anode and theMg/Ag as the cathode, a voltage of 10 V was applied by means of a DCpower source, whereupon the green, red and blue three-color light wasemitted in stripes.

EXAMPLE 18

[0271] A eighteenth working example is described below.

[0272] As shown in FIG. 33A, the ITO electrodes 2, blue-colorphotoemissive hole transport layer 50, red-color photoemission layers 31and hole block layers 34 were formed on the surface of the substrate 1in the same manner as in Example 14 except that the green-colorphotoemission layers were not formed.

[0273] Next, a green-color photoemissive electron transport layer 33 awith a thickness of 100 nm, consisting of tris(8-quinolinolato)aluminum,was formed by vacuum deposition, and thereafter the cathode 4 was formedin the same manner as in Example 14 to obtain an organic-EL device.

[0274] To the device thus obtained, setting the ITO as the anode and theMg/Ag as the cathode, a voltage of 10 V was applied by means of a DCpower source, whereupon the green, red and blue three-color light wasemitted in stripes.

EXAMPLE 19

[0275] A nineteenth working example is described below.

[0276] An organic-EL device having the green-color photoemissiveelectron transport layer 33 a was obtained in the same manner as inExample 18 except that the green-color photoemissive electron transportlayer 33 a was formed using a photosensitive composition for forminggreen-color photoemissive electron transport layer, comprising 0.6 g ofpolymethyl methacrylate, 0.15 g of the aromatic bisazide represented bythe structural formula (23), 0.05 g of coumarin-6, 0.35 g of the sameoxadiazole derivative as that used in Example 1 and 10 g ofN-methylpyrrolidone, which was patternwise printed by flexographicprinting at the center area of the substrate, followed by exposure anddevelopment under the same conditions as those for the otherphotoemission layers.

[0277] To the device thus obtained, setting the ITO as the anode and theMg/Ag as the cathode, a voltage of 10 V was applied by means of a DCpower source, whereupon the green, red and blue three-color light wasemitted in stripes.

EXAMPLE 20

[0278] A twentieth working example is described below.

[0279] The ITO electrodes, blue-color photoemissive hole transportlayer, red-color photoemission layers, hole block layers and green-colorphotoemissive electron transport layer were formed on the surface of thein the same manner as in Example 19.

[0280] Next, as shown in FIG. 34A, on the surface of the green-colorphotoemissive electron transport layer 33 a, the electron transportlayer 6 was formed in the same manner as in Example 14 except that thearomatic bisazide was mixed in an amount of 0.35 g. Thereafter, thecathode 4 was formed in the same manner as in Example 14 to obtain anorganic-EL device shown in FIG. 34B.

[0281] To the device thus obtained, setting the ITO as the anode and theMg/Ag as the cathode, a voltage of 10 V was applied by means of a DCpower source, whereupon the green, red and blue three-color light wasemitted in stripes.

[0282] According to the present invention, the photosensitivecomposition can readily cure upon exposure in air, and hence the devicescan be mass-produced at a low cost in a large quantity. Also, thephotosensitive composition has so high a viscosity that it isunnecessary to provide any gap between the photosensitive compositionformed into a film and the mask, and hence precise exposure can beeffected. Thus, the hole transport layer, photoemission layers and/orelectron transport layer can be formed in well-precise and finepatterns.

[0283] While we have shown and described several embodiments inaccordance with our invention, it should be understood that disclosedembodiments are susceptible of changes and modifications withoutdeparting from the scope of the invention. Therefore, we do not intendto be bound by the details shown and described herein but intend tocover all such changes and modifications a fall within the ambit of theappended claims.

We claim:
 1. An organic-electroluminescence device comprising aphotoemission layer containing a high-molecular compound having beencross-linked with a divalent organic group represented by the followingFormula (1) or (2).

wherein X, Y and Z are each a divalent organic group containing at leastone of an allyl group, an aryl group, an alkylene group, an alkyl group,an amide group, an ester group, a nitrile group and a carbonyl group;And R¹ to R⁶ are each a hydrogen atom or a monovalent organic groupcontaining at least one of an allyl group, an aryl group, an alkylenegroup, an alkyl group, an amide group, an ester group, a nitrile groupand a carbonyl group.
 2. The organic-electroluminescence deviceaccording to claim 1, wherein said high-molecular compound has beencross-linked with at least one photo-crosslinkable group of a cinnamoylgroup, a cinnamylidene group, a chalcone residual group, an isocoumarinresidual group, a 2,5-dimethoxystilbene residual group, a thymineresidual group, a styrylpyridinium residual group, an α-phenylmaleimideresidual group, an anthracene residual group and a 2-pyrrone residualgroup.
 3. The organic-electroluminescence device according to claim 1,wherein said high-molecular compound has been cross-linked with anaromatic bisazide.
 4. The organic-electroluminescence device accordingto claim 1, wherein said photoemission layer comprises a plurality oflayers comprising a first photoemission pattern comprised of afirst-color luminescent material, a second photoemission patterncomprised of a second-color luminescent material and a thirdphotoemission pattern comprised of a third-color luminescent material,and at least one of the first-color luminescent material, thesecond-color luminescent material and the third-color luminescentmaterial contains said high-molecular compound.
 5. Theorganic-electroluminescence device according to claim 4, wherein atleast one of said first photoemission pattern, said second photoemissionpattern and said third photoemission pattern serves also as at least oneof an electron transport layer and a hole transport layer.
 6. Theorganic-electroluminescence device according to claim 1, which furthercomprises a hole transport layer containing a first-color luminescentmaterial; said photoemission layer comprising a plurality of layerscomprising a hole block pattern comprised of a material capable ofblocking the transport of holes, a second photoemission patterncomprised of a second-color luminescent material and a thirdphotoemission pattern comprised of a third-color luminescent material,and at least one of the second-color luminescent material and thethird-color luminescent material containing said high-molecularcompound.
 7. The organic-electroluminescence device according to claim6, wherein at least one of said second photoemission pattern and saidthird photoemission pattern serves also as an electron transport layer.8. The organic-electroluminescence device according to claim 1, whichcomprises a hole transport layer containing a high-molecular compoundhaving been cross-linked with a divalent organic group represented bythe following Formula (1):

wherein X and Y are each a divalent organic group represented by any ofthe following structural formulas, Formulas (3) to (5):

R¹, R²2, R⁴ and R⁵ are each a hydrogen atom, and R³ and R⁶ are each aphenyl group.
 9. The organic-electroluminescence device according toclaim 1, which comprises an electron transport layer containing ahigh-molecular compound having been cross-linked with a divalent organicgroup represented by the following Formula (1):

wherein X and Y are each a divalent organic group represented by thefollowing structural formula, Formula (6):

R¹, R²2, R⁴ and R⁵ are each a hydrogen atom and R³ and R⁶ are each aphenyl group.
 10. An organic-electroluminescence display systemcomprising the organic-electroluminescence device according to any oneof clams
 1. 11. A process for producing an organic-electroluminescencedevice; the process comprising the steps of: forming a film of ahigh-molecular compound composition which contains a high-molecularcompound having a divalent organic group represented by the followingFormula (7); followed by exposure and then development to form aphotoemission layer in a prescribed pattern,

wherein X is a divalent organic group containing at least one of anallyl group, an aryl group, an alkylene group, an alkyl group, an amidegroup, an ester group, a nitrile group and a carbonyl group; and R⁷ toR⁹ are each a hydrogen atom or a monovalent organic group containing atleast one of an allyl group, an aryl group, an alkylene group, an alkylgroup, an amide group, an ester group, a nitrile group and a carbonylgroup.
 12. A process for producing an organic-electroluminescencedevice; the process comprising the steps of: forming a film of ahigh-molecular compound composition which contains i) a high-molecularcompound having a divalent organic group represented by the followingFormula (8) and ii) a bisazide compound; followed by exposure and thendevelopment to form a photoemission layer in a prescribed pattern,

wherein W is a monovalent organic group containing at least one of anallyl group, an aryl group, an alkylene group, an alkyl group, an amidegroup, an ester group, a nitrile group, a carbonyl group, a carbazolegroup and a fluorene group.